There is an old theory that in the center of every galaxy there is a super massive black hole causing it to spin, effectively keeping it alive, as it eats the galaxy. The difference between our galaxy and Andromeda, is that the black hole is a different size. Black holes get bigger as they consume everything around them, the bigger they are, the more they consume, and the cycle continues.
Our black hole, the one in the center of the milky-way , is finally going to start eating in about 2 years, and the awesome part is that were close enough to watch it feed.
Sagittarius A* is a super massive black hole, it is estimated that it has about as much mass as four billion suns stuffed into an orbit the size of Uranus. This means, that anything that gets close to the hole will effectively get eaten alive, in this case, a gas cloud. Astronomers say that were in the perfect position to watch the black hole consume the gas cloud, in 2013, the mayhem will tear it apart. The light emitted by Sagittarius A should increase by anywhere between 100 to a 1000 times fold as half of the cloud gets consumed while the other half is thrown back into space.
The destruction is going to start in 2013 and should end around 2021, during this time astronomers will be able to study what happens around the black hole to gain a better understanding of what this universe is all about.